Summary
Objectives: A study was performed to evaluate the lumbar vertebrae of domestic rabbits using
computed tomography (CT) in order to identify safe corridors for implant insertion.
Methods: Computed tomography imaging of 20 adult New Zealand white rabbits was evaluated using
three-dimensional multi -planar reconstruction, and safe corridors were determined.
Following corridor determination, implant placement was performed, and imaging was
repeated.
Results: The cranial and caudal endplates contained the majority of the vertebral bone stock,
and were an average of 3.14 and 3.30 mm in length, respectively. The mean safe corridor
angle was 62.9 degrees (range: 58.8–66.7), and the mean width of the corridor was
2.03 mm (range: 1.60– 2.07). Post-placement imaging revealed that 35% of the pins
demonstrated errors of placement, most commonly canal impingement. Conclusions: The results of the corridor evaluation indicate that an insertion angle of approximately
60 degrees relative to the sagittal midline is appropriate for implant insertion in
the lumbar vertebrae of New Zealand white rabbits. Additionally, due to the hourglass
shape of rabbit vertebrae, the endplates provide maximal bone stock for implant purchase,
so insertion should be attempted in these regions. However, the high percentage of
errors in placement indicate the need to more clearly define entry points to access
the canal, and highlight the challenges of appropriate placement in the small bones
of rabbits.
Keywords
Computed tomography - implant insertion - rabbit - spine - lumbar vertebrae
